This isn't an attempt at complete answer to your question, and I'm not an expert, a teacher, or anything besides a human who has dabbled with meditation and read a lot about Buddhism (and derived more-or-less secular frameworks such as mindfulness), depression, anxiety, neuroscience, spirituality, etc. over the last 15-20 years.
I'm speaking to two of your points, I think:
1) "isn't our whole life a sequence of meditations? Because we always focus on something"
2) "aren’t we doing [sit peacefully and observe your thoughts] anyway on a regular basis without introducing a word for it?"
In my direct personal experience, sitting in awareness, noticing thoughts and sensations, etc. is simply a materially different experience from... the rest of my time when I'm not doing that. It's materially different from when I'm focusing on an activity like coding (perhaps in a deep state of focus or "flow" [0]) or just habitually/pathologically scrolling through HN.
Did you ever get fully engrossed in a coding session and "lose time"? And eventually
you "came around" or "landed" and realized you were "back" and 2 hours had gone by in deep focus? Did you ever realize that you'd been ruminating about some stupid thing for ages? E.g. repeatedly going over a difficult interaction from earlier in the day, or thinking about a difficult interaction that's coming up tomorrow and imagining how it might go? Did you ever snap out of that?
That feeling of "huh... I'm back - here I am." - that's what I am recruiting when I deliberately practice mindfulness. And then I get distracted... and when I notice, I bring my attention back... repeat.
To the second point of yours I quoted, i.e. are we doing this "anyway" on a regular basis? Maybe you are. For me, regular moment-to-moment thinking is generally not the same as mindfulness. I'm thinking, but I'm basically lost in the thoughts. I'm not observing them, I'm just thinking them - or they're thinking me. (And not just thoughts - this all applies equally well to emotional, interoceptive, and sensory experience.) Mindfully observing my experience is materially different, although I do get flashes of it throughout the day without reaching for it deliberately. Whether that's something I had before I started sporadic practice and just didn't have words for, or something the practice has unlocked for me, I can't say, because I can't faithfully recall what my moment-to-moment experience was like that long ago.
Maybe you're experiencing mindfulness frequently throughout your daily life, so you don't notice anything different when you set out to practice it deliberately. Maybe when you practice it you are getting lost in thought and not noticing. We'll never know, given the subjectivity of the experience and our limited tools for communicating about it, but I enjoyed the attempt :)
I'm speaking to two of your points, I think:
1) "isn't our whole life a sequence of meditations? Because we always focus on something"
2) "aren’t we doing [sit peacefully and observe your thoughts] anyway on a regular basis without introducing a word for it?"
In my direct personal experience, sitting in awareness, noticing thoughts and sensations, etc. is simply a materially different experience from... the rest of my time when I'm not doing that. It's materially different from when I'm focusing on an activity like coding (perhaps in a deep state of focus or "flow" [0]) or just habitually/pathologically scrolling through HN.
Did you ever get fully engrossed in a coding session and "lose time"? And eventually you "came around" or "landed" and realized you were "back" and 2 hours had gone by in deep focus? Did you ever realize that you'd been ruminating about some stupid thing for ages? E.g. repeatedly going over a difficult interaction from earlier in the day, or thinking about a difficult interaction that's coming up tomorrow and imagining how it might go? Did you ever snap out of that?
That feeling of "huh... I'm back - here I am." - that's what I am recruiting when I deliberately practice mindfulness. And then I get distracted... and when I notice, I bring my attention back... repeat.
To the second point of yours I quoted, i.e. are we doing this "anyway" on a regular basis? Maybe you are. For me, regular moment-to-moment thinking is generally not the same as mindfulness. I'm thinking, but I'm basically lost in the thoughts. I'm not observing them, I'm just thinking them - or they're thinking me. (And not just thoughts - this all applies equally well to emotional, interoceptive, and sensory experience.) Mindfully observing my experience is materially different, although I do get flashes of it throughout the day without reaching for it deliberately. Whether that's something I had before I started sporadic practice and just didn't have words for, or something the practice has unlocked for me, I can't say, because I can't faithfully recall what my moment-to-moment experience was like that long ago.
Maybe you're experiencing mindfulness frequently throughout your daily life, so you don't notice anything different when you set out to practice it deliberately. Maybe when you practice it you are getting lost in thought and not noticing. We'll never know, given the subjectivity of the experience and our limited tools for communicating about it, but I enjoyed the attempt :)
[0] https://www.amazon.com/Flow-Psychology-Experience-Perennial-...